Hybrid module

ABSTRACT

A rotor assembly for a hybrid module includes a rotor carrier, a rotor segment, an end ring, a first spacer, a second spacer, and a compressed spring. The rotor carrier includes a first outer cylindrical surface and a radial surface, and the rotor segment is installed on the first outer cylindrical surface. The end ring is fixed to the rotor carrier and arranged for fixing to an engine flexplate. The first spacer is disposed axially between the rotor segment and the radial surface, and the second spacer is disposed axially between the rotor segment and the end ring. The compressed spring is disposed axially between the end ring and the second spacer to press the first spacer, the second spacer, and the rotor segment against the radial surface for frictional torque transmission between the rotor segment and the rotor carrier.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 62/970,437, filed Feb. 5, 2020, the disclosure of whichis incorporated in its entirety by reference herein.

TECHNICAL FIELD

The present disclosure relates generally to a hybrid module, and morespecifically to a rotor assembly for a hybrid module.

BACKGROUND

Hybrid modules are known. One example is shown in commonly-assignedUnited States Patent Application Publication No. 2020/0040974 to Payneet al., titled HYBRID MODULE CONFIGURATION, hereby incorporated byreference as if set forth fully herein.

SUMMARY

Example embodiments broadly comprise a rotor assembly for a hybridmodule including a rotor carrier, a rotor segment, an end ring, a firstspacer, a second spacer, and a compressed spring. The rotor carrierincludes a first outer cylindrical surface and a radial surface, and therotor segment is installed on the first outer cylindrical surface. Theend ring is fixed to the rotor carrier and arranged for fixing to anengine flexplate. The first spacer is disposed axially between the rotorsegment and the radial surface, and the second spacer is disposedaxially between the rotor segment and the end ring. The compressedspring is disposed axially between the end ring and the second spacer topress the first spacer, the second spacer, and the rotor segment againstthe radial surface for frictional torque transmission between the rotorsegment and the rotor carrier.

In an example embodiment, the compressed spring is a Belleville springor a diaphragm spring. In an example embodiment, each of the firstspacer and the second spacer comprises a non-magnetic material. In someexample embodiments, the end ring includes a plurality of threaded holesfor receiving bolts for fixing the engine flexplate to the end ring, ora plurality of studs fixed to the end ring for receiving nuts for fixingthe engine flexplate to the end ring. In an example embodiment, theplurality of threaded holes or the plurality of studs is disposedradially outside of the first outer cylindrical surface.

In an example embodiment, a one of the rotor segment or the rotorcarrier comprises a key, the other of the rotor segment or the rotorcarrier comprises a keyway, and the key is disposed in the keyway torotationally position the rotor segment relative to the rotor carrier.In an example embodiment, the rotor assembly includes a pilot fixed tothe rotor carrier for positioning the rotor assembly in an enginecrankshaft bore. In an example embodiment, the rotor assembly includes abalance weight fixed to a second outer cylindrical surface of the rotorcarrier. In an example embodiment, the rotor assembly includes a torqueconverter impeller fixed to the rotor carrier.

Other example aspects broadly comprise a hybrid module including therotor assembly and a stator assembly. The stator assembly is disposedradially outside of the rotor assembly and is fixed to a transmissioncase for a multi-speed planetary transmission.

BRIEF DESCRIPTION OF THE DRAWINGS

The single FIGURE illustrates a top-half cross-sectional view of ahybrid module according to an example aspect of the present disclosure.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described herein. It should beappreciated that like drawing numbers appearing in different drawingviews identify identical, or functionally similar, structural elements.Also, it is to be understood that the disclosed embodiments are merelyexamples and other embodiments can take various and alternative forms.The figures are not necessarily to scale; some features could beexaggerated or minimized to show details of particular components.Therefore, specific structural and functional details disclosed hereinare not to be interpreted as limiting, but merely as a representativebasis for teaching one skilled in the art to variously employ theembodiments. As those of ordinary skill in the art will understand,various features illustrated and described with reference to any one ofthe figures can be combined with features illustrated in one or moreother figures to produce embodiments that are not explicitly illustratedor described. The combinations of features illustrated providerepresentative embodiments for typical applications. Variouscombinations and modifications of the features consistent with theteachings of this disclosure, however, could be desired for particularapplications or implementations.

The terminology used herein is for the purpose of describing particularaspects only, and is not intended to limit the scope of the presentdisclosure. Unless defined otherwise, all technical and scientific termsused herein have the same meaning as commonly understood to one ofordinary skill in the art to which this disclosure belongs. Although anymethods, devices or materials similar or equivalent to those describedherein can be used in the practice or testing of the disclosure, thefollowing example methods, devices, and materials are now described.

The single FIGURE illustrates a top-half cross-sectional view of hybridmodule 100 according to an example aspect of the present disclosure.Hybrid module 100 includes rotor assembly 102 and stator assembly 104.Rotor assembly 102 includes rotor carrier 106, rotor segment 108, endring 110, spacer 112, spacer 114, and compressed spring 116. Rotorcarrier 106 includes outer cylindrical surface 118 and radial surface,or shoulder, 120. The rotor segment is installed on outer cylindricalsurface 118. Segment 108 may be a stack of segments, for example. Theend ring, is fixed to the rotor carrier and arranged for fixing toengine flexplate 122. Spacer 112 is disposed axially between the rotorsegment and the radial surface, and spacer 114 is disposed axiallybetween the rotor segment and the end ring.

The compressed spring is disposed axially between the end ring andspacer 114, and applies a rotor clamping force to press spacers 112 and114, and the rotor segment, against the radial surface for frictionaltorque transmission between the rotor segment and the rotor carrier.That is, during assembly, the rotor carrier is axially held and thespring is compressed by a force pressing on the end ring. Once thedesired compression force is achieved, the end ring is fixed to therotor carrier by weld 123. Some embodiments (not shown) may includeselect fit shimming or machining, to reduce variation of a flex plateconnection location on the end ring due to tolerances from stacked rotorsegments.

The compressed spring is a thick Belleville spring or a thick diaphragmspring that is compressed to flat, for example. Each of spacers 112 and114 include a non-magnetic material. For example, spacers 112 and 114may be made from a metal such as brass; stainless steel or aluminum, ora nonmetallic material such as plastic, a polymer, or a ceramic.Although certain materials are listed as examples, spacers 112 and 114may be made from other non-magnetic materials.

End ring 110 includes threaded holes 124 for receiving bolts (not shown)for fixing the engine flexplate to the end ring. Other embodiments (notshown) may include studs (not shown) fixed to the end ring for receivingnuts for fixing the engine flexplate to the end ring. Engine block 126includes access hatch 127 for securing the bolts or nuts to secure therotor carrier to the engine flexplate. Flexplate 122 is fixed to enginecrankshaft 128 by bolts 129. As shown in the FIGURE, holes 124 aredisposed radially outside of outer cylindrical surface 118.

Rotor segment 108 includes key 130 and rotor carrier 106 includes keyway132. The key is disposed in the keyway to rotationally position therotor segment relative to the rotor carrier. Other embodiments (notshown) may include the key in the rotor carrier and the keyway in therotor segment, for example. The rotor assembly includes pilot 134 fixedto the rotor carrier for positioning the rotor assembly in enginecrankshaft bore 136, and balance weight 138 fixed to outer cylindricalsurface 140 of rotor carrier 106.

The hybrid module includes torque converter assembly 142 includingtorque converter impeller 144 is fixed to the rotor carrier at weld 146,for example. The impeller and rotor carrier form a housing for thetorque converter. Lockup clutch 148, damper 150, turbine 152 and torqueconverter stator 154 are disposed within the housing. Lockup clutch 148includes piston 156 and clutch plates 158 for torque transmissionbetween the rotor carrier and the damper. Some of the clutch plates aredrivingly engaged with the rotor carrier through drive ring 160, fixedto the rotor carrier and sealed to the piston, and other clutch platesare drivingly engaged with the damper through cover plate 162. Backingplate 164, fixed to the rotor carrier, reacts axial force from piston156 when the lockup clutch is engaged.

Stator assembly 104 is disposed radially outside of the rotor assemblyand is fixed to transmission case 166 for a multi-speed planetarytransmission. Stator assembly 104 includes stator carrier 168, statorsegment 170, and water jacket 172. Stator segment 170 may be a stack ofstator segments, for example. The stator carrier includes innercylindrical surface 174 and the stator segment is installed in the innercylindrical surface by shrink fitting, for example. In other words, thestator carrier is heated to expand the inner cylindrical surface and thestator segment is installed. Once the stator carrier cools, the innercylindrical surface shrink fits to the stator segment. The water jacketis fixed to the stator carrier to enclose sealed chamber 176therebetween. The water jacket is fixed to the stator carrier bycircumferential welds 178 and 180 at opposite ends of the sealed chamberand axially outside of stator segment 170. Welds 178 and 180 may belaser welds, for example.

Stator assembly 104 includes fluid port 182 fixed to the water jacketand arranged to guide a fluid into or out of the sealed chamber to coolthe stator assembly. That is, the fluid port can be connected to a tubeor hose that circulates a cooling fluid (e.g., water) through the sealedchamber to extract heat from the stator assembly. The fluid can beconstantly circulated or only circulated when the temperature of thestator assembly exceeds a threshold value. A circulation rate of thefluid may also be adjusted based on a temperature of the stator assemblyof an electrical power consumption of the hybrid module, for example.

Stator carrier 168 is arranged for fixing the stator assembly to thetransmission case. That is, stator carrier 168 includes aperture 184 forreceiving bolt 186 threaded into the transmission case to secure thecomponents. Although, the stator carrier is shown fixing the statorassembly to the transmission case, the water jacket may fix the statorassembly to the transmission case in a similar manner in otherembodiments (not shown).

Stator assembly 104 includes resolver stator 188. The water jacketincludes extension 190 extending axially away from the stator segmentand radially inward, and the resolver stator is fixed to the extension.Although the extension is shown extending from the water jacket, otherembodiments (not shown) may include the extension extending from thestator carrier. As shown in the FIGURE, the resolver stator is fixed tothe extension by rivet 192 although other fixing methods (e.g., bolting,staking, adhesives) may be employed in other embodiments (not shown).Stator assembly 104 includes high voltage bus bar 194 electricallyconnected to the stator segment, and the extension includes opening 196for connecting the high voltage bus bar to a high voltage transmissionconnector (not shown).

Stator assembly 104 also includes resolver rotor 198 fixed to torqueconverter impeller 144. As shown in the FIGURE, impeller 144 includesring 200 fixed to the impeller and resolver rotor 198 staked to thering. Resolver rotor 198 is axially aligned with the resolver stator. Inother words, a line can be drawn normal to axis 202 that extends throughboth resolver stator 188 and resolver rotor 198.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms is encompassed by theclaims. The words used in the specification are words of descriptionrather than limitation, and it is understood that various changes can bemade without departing from the spirit and scope of the disclosure. Aspreviously described, the features of various embodiments can becombined to form further embodiments of the disclosure that may not beexplicitly described or illustrated. While various embodiments couldhave been described as providing advantages or being preferred overother embodiments or prior art implementations with respect to one ormore desired characteristics, those of ordinary skill in the artrecognize that one or more features or characteristics can becompromised to achieve desired overall system attributes, which dependon the specific application and implementation. These attributes caninclude, but are not limited to cost, strength, durability, life cyclecost, marketability, appearance, packaging, size, serviceability,weight, manufacturability, ease of assembly, etc. As such, to the extentany embodiments are described as less desirable than other embodimentsor prior art implementations with respect to one or morecharacteristics, these embodiments are not outside the scope of thedisclosure and can be desirable for particular applications.

LIST OF REFERENCE NUMBERS

-   -   100 Hybrid module    -   102 Rotor assembly    -   104 Stator assembly    -   106 Rotor carrier    -   108 Rotor segment    -   110 End ring    -   112 Spacer (first)    -   114 Spacer (second)    -   116 Compressed spring    -   118 Outer cylindrical surface (first)    -   120 Radial surface    -   122 Engine flexplate    -   123 Weld (end ring/rotor carrier)    -   124 Threaded holes    -   126 Engine block    -   127 Access hatch    -   128 Engine crankshaft    -   129 Bolts (crankshaft/flexplate)    -   130 Key    -   132 Keyway    -   134 Pilot    -   136 Engine crankshaft bore    -   138 Balance weight    -   140 Outer cylindrical surface (second)    -   142 Torque converter assembly    -   144 Torque converter impeller    -   146 Weld (impeller/rotor carrier)    -   148 Lockup clutch    -   150 Damper    -   152 Turbine    -   154 Torque converter stator    -   156 Piston    -   158 Clutch plates    -   160 Drive ring    -   162 Cover plate    -   164 Backing plate    -   166 Transmission case    -   168 Stator carrier    -   170 Stator segment    -   172 Water jacket    -   174 Inner cylindrical surface    -   176 Sealed chamber    -   178 Circumferential weld    -   180 Circumferential weld    -   182 Fluid port    -   184 Aperture    -   186 Bolt    -   188 Resolver stator    -   190 Extension    -   192 Rivet    -   194 High voltage bus bar    -   196 Opening    -   198 Resolver rotor    -   200 Ring    -   202 Axis.

What is claimed is:
 1. A rotor assembly for a hybrid module, comprising:a rotor carrier comprising a first outer cylindrical surface and aradial surface; a rotor segment installed on the first outer cylindricalsurface; an end ring, fixed to the rotor carrier and arranged for fixingto an engine flexplate; a first spacer disposed axially between therotor segment and the radial surface; a second spacer disposed axiallybetween the rotor segment and the end ring; and a compressed springdisposed axially between the end ring and the second spacer to press thefirst spacer, the second spacer, and the rotor segment against theradial surface for frictional torque transmission between the rotorsegment and the rotor carrier.
 2. The rotor assembly of claim 1 whereinthe compressed spring is a Belleville spring or a diaphragm spring. 3.The rotor assembly of claim 1 wherein each of the first spacer and thesecond spacer comprises a non-magnetic material.
 4. The rotor assemblyof claim 1 wherein the end ring comprises: a plurality of threaded holesfor receiving bolts for fixing the engine flexplate to the end ring; ora plurality of studs fixed to the end ring for receiving nuts for fixingthe engine flexplate to the end ring.
 5. The rotor assembly of claim 4wherein the plurality of threaded holes or the plurality of studs isdisposed radially outside of the first outer cylindrical surface.
 6. Therotor assembly of claim 1 wherein: a one of the rotor segment or therotor carrier comprises a key; the other of the rotor segment or therotor carrier comprises a keyway; and the key is disposed in the keywayto rotationally position the rotor segment relative to the rotorcarrier.
 7. The rotor assembly of claim 1 further comprising a pilotfixed to the rotor carrier for positioning the rotor assembly in anengine crankshaft bore.
 8. The rotor assembly of claim 1 furthercomprising a balance weight fixed to a second outer cylindrical surfaceof the rotor carrier.
 9. The rotor assembly of claim 1 furthercomprising a torque converter impeller fixed to the rotor carrier.
 10. Ahybrid module comprising: the rotor assembly of claim 1; and a statorassembly disposed radially outside of the rotor assembly and fixed to atransmission case for a multi-speed planetary transmission.